Switched capacitor voltage regulator with high efficiency over a wide voltage range

1. A voltage regulator device, comprising: a switched capacitor voltage regulator to receive an input voltage and to provide an output voltage to a load; and a control unit to receive information related to a desired output voltage for the switched capacitor voltage regulator and to determine a desired input voltage for the switched capacitor voltage regulator based on the desired output voltage, wherein the input voltage is selected to provide an output voltage that meets either a continuous or fine voltage step requirement of a load and a discrete voltage level requirement of the switched capacitor voltage regulator, and wherein the output voltage is a function of the input voltage, a constant time value representing a step down voltage conversion ratio, and integers providing switched capacitor voltage regulator efficiency.

2. The voltage regulator device of claim 1 , wherein the control unit is further configured to provide control information related to the desired input voltage.

3. The voltage regulator device of claim 1 , wherein the load includes a processor and wherein the information related to the desired output voltage includes information related to processor performance demands.

4. The voltage regulator device of claim 3 , wherein the control unit is configured to determine the desired input voltage based on information related to one or more of a processor voltage identification, a processor load prediction and a conversion ratio of the switched capacitor voltage regulator.

5. The voltage regulator device of claim 3 , wherein the switched capacitor voltage regulator, the control unit, and the processor are co-located on a same integrated circuit die.

6. A method of operating a voltage regulator, comprising: providing a buck converter having a variable duty cycle; receiving an input voltage at an input of the buck converter; providing an intermediate voltage at an output of the buck converter; providing a switched capacitor voltage regulator; receiving the intermediate voltage at an input of the switched capacitor voltage regulator; providing an output voltage from the output of the switched capacitor voltage regulator to a load; providing a controller; receiving at the controller, information related to a desired output voltage for the switched capacitor voltage regulator; determining a desired intermediate voltage for the switched capacitor voltage regulator based on the desired output voltage; adjusting at the buck converter, the intermediate voltage based on control information received from the controller; and adjusting the duty cycle of the buck converter based on control information received from the controller.

7. The method of operating a voltage regulator of claim 6 , further comprising: providing control information related to the desired input voltage.

8. The method of operating a voltage regulator of claim 7 , further comprising: adjusting at least one of the input voltage and a conversion ratio for the switched capacitor voltage regulator based on the control information.

9. The method of operating a voltage regulator of claim 6 , wherein providing the output voltage from the switched capacitor voltage regulator to the load comprises providing the output voltage from the switched capacitor voltage regulator to a processor, and wherein the information related to the desired output voltage includes information related to processor performance demands.

10. The method of operating a voltage regulator of claim 9 , wherein determining the desired input voltage for the switched capacitor voltage regulator based on the desired output voltage comprises determining the desired input voltage based on information related to one or more of a processor voltage identification, a processor load prediction and a conversion ratio of the switched capacitor voltage regulator.

11. An electronic system, comprising: a first voltage regulator device to receive an input voltage and to provide an intermediate voltage; a second voltage regulator device to receive the intermediate voltage and to provide an output voltage, wherein the second voltage regulator device comprises a switched capacitor voltage regulator; a load circuit coupled to the output voltage; and a control unit coupled between the load circuit and the first voltage regulator device, wherein the control unit is configured to receive information related to a desired output voltage for the switched capacitor voltage regulator and to determine a desired intermediate voltage for the switched capacitor voltage regulator based on the desired output voltage, wherein the control unit is further configured to provide control information related to the desired intermediate voltage to the first voltage regulator, wherein the first voltage regulator is configured to adjust the intermediate voltage based on the control information received from the control unit, wherein the first voltage regulator comprises a buck converter having a variable duty cycle and wherein the buck converter is configured to adjust the duty cycle based on the control information received from the control unit.

12. The electronic system of claim 11 , wherein the load includes a processor and wherein the information related to the desired output voltage includes information related to processor performance demands.

13. The electronic system of claim 12 , wherein the control unit is configured to determine the desired intermediate voltage based on information related to one or more of a processor voltage identification, a processor load prediction and a conversion ratio of the switched capacitor voltage regulator.

14. The electronic system of claim 12 , wherein the switched capacitor voltage regulator, the control unit, and the processor are co-located on a same integrated circuit die.